  <header class="p-3 bg-dark text-white">
    <div class="container">
      <div class="d-flex flex-wrap align-items-center justify-content-center justify-content-lg-start">
        <a href="/" class="d-flex align-items-center mb-2 mb-lg-0 text-white text-decoration-none">
          <svg class="bi me-2" width="40" height="32" role="img" aria-label="Bootstrap"><use xlink:href="#bootstrap"/></svg>
        </a>

        <ul class="nav col-12 col-lg-auto me-lg-auto mb-2 justify-content-center mb-md-0">
          <li><a href="/" class="nav-link px-2 text-secondary">Home</a></li>
          <li><a href="#" class="nav-link px-2 text-white">Features</a></li>
          <li><a href="#" class="nav-link px-2 text-white">Pricing</a></li>
          <li><a href="#" class="nav-link px-2 text-white">FAQs</a></li>
          <li><a href="#" class="nav-link px-2 text-white">About</a></li>
        </ul>

        <form class="col-12 col-lg-auto mb-3 mb-lg-0 me-lg-3">
          <input type="search" class="form-control form-control-dark" placeholder="Search..." aria-label="Search">
        </form>

        <div class="text-end">
        <% unless user_signed_in? %>
         <div>
              <button type="button" class="btn btn-outline-light me-2" onclick="window.location.href='/users/sign_in'">登录</button>
              <button type="button" class="btn btn-warning" onclick="window.location.href='/users/sign_up'">注册</button>
         </div>
         <% end %>
        <% if user_signed_in? %>
        <div>
            <%= link_to destroy_user_session_path, data: {turbo_method: "delete", turbo_confirm: "确认删除吗？"} do %>
             你好！<%=current_user.email%> <button type="button" class="btn btn-warning"> 退出</button>
            <% end %>
        </div>
        <% end %>
  
        </div>
      </div>
    </div>
  </header>
